When working out on the track, sean normally averages x laps per minute, while jill averages y laps
per minute. during one workout, sean and jill ran simultaneously for 40 minutes and completed a
combined total of 53 laps. during a second workout in which they ran a continuous relay, sean ran for 30 minutes, jill ran for 28 minutes, and they completed 38.5 laps. find the values of x and y.